Semiconductor device

ABSTRACT

Disclosed in an embodiment is a semiconductor device comprising a semiconductor structure, which comprises a first conductive semiconductor layer, a second conductive semiconductor layer, and an active layer disposed between the first conductive semiconductor layer and the second conductive semiconductor layer, wherein: the first conductive semiconductor layer comprises a first super lattice layer comprising a plurality of first sub layers and a plurality of second sub layers, the first and second sub layers being alternately arranged; the semiconductor structure emits ions of indium, aluminum, and a first and second dopant during a primary ion irradiation; the intensity of indium ions emitted from the active layer includes a maximum indium intensity peak; the doping concentration of the first dopant emitted from the first conductive semiconductor layer includes a maximum concentration peak; the maximum indium intensity peak is disposed to be spaced from the maximum concentration peak in a first direction; the intensity of indium ions emitted from the plurality of first sub layers has a plurality of first indium intensity peaks; the doping concentration of the first dopant emitted from the plurality of first sub layers has a plurality of first concentration peaks; and the plurality of first indium intensity peaks and the plurality of first concentration peaks are disposed between the maximum indium intensity peak and the maximum concentration peak.

TECHNICAL FIELD

An embodiment relates to a semiconductor device.

BACKGROUND ART

A semiconductor device including a compound, such as GaN and AlGaN, hasmany advantages, such as wide and adjustable band-gap energy, and thusmay be diversely used for light-emitting devices, light-receivingdevices, various diodes, and the like.

In particular, a light-emitting device, such as a light-emitting diodeor a laser diode, using a III-V group or II-VI group compoundsemiconductor material can realize various colors, such as red, green,blue, or ultraviolet light due to the development of thin-film growthtechnology and device materials. Also, the light-emitting device canrealize efficient white light by using a fluorescent material orcombining colors and has the advantages of low power consumption,semi-permanent lifetime, high response speed, safety, and environmentalfriendliness as compared to existing light sources such as fluorescentlamps and incandescent lamps.

Moreover, due to the development of device materials, when alight-receiving device, such as a photodetector or a solar cell, isfabricated using a III-V group or II-VI group compound semiconductormaterial, the light-receiving device generates a photocurrent byabsorbing light in various wavelength regions, and thus it is possibleto use light in various wavelength regions from a gamma-ray region to aradio-wave region. Also, the light-receiving device has the advantagesof fast response time, safety, environmental friendliness, and ease ofadjustment of device materials and thus may be easily used for powercontrol or ultra-high frequency circuits or communication modules.

Therefore, the applications of semiconductor devices are being expandedto transmission modules of optical communication means, light-emittingdiode backlights which replace cold cathode fluorescence lamps (CCFLs)constituting the backlights of liquid crystal display (LCD) devices,white light-emitting diode lighting devices which may replacefluorescent lamps or incandescent lamps, vehicle headlights, trafficlights, sensors for sensing gas or fire, and the like. Also, theapplications of semiconductor devices may be expanded to high-frequencyapplication circuits, other power control devices, and communicationmodules.

However, in a conventional semiconductor device, the surface of asemiconductor layer may be roughened so that excessive stress may beapplied to an active layer. Thus, there are problems in that electricaland optical characteristics are deteriorated.

DISCLOSURE Technical Problem

An embodiment is directed to providing a semiconductor device in which asurface roughness of an active layer is improved.

An embodiment is also directed to providing a semiconductor device withimproved optical power.

An embodiment is also directed to providing a semiconductor device withimproved current spreading efficiency.

Objectives to be solved by embodiments of the present invention are notlimited to the above-described objectives and will include objectivesand effects which can be identified by solutions for the objectives andthe embodiments described below.

Technical Solution

One aspect of the present invention provides a semiconductor deviceincluding a semiconductor structure including a first conductivesemiconductor layer, a second conductive semiconductor layer, and anactive layer disposed between the first conductive semiconductor layerand the second conductive semiconductor layer, wherein the firstconductive semiconductor layer includes a first superlattice layerincluding a plurality of first sub layers and a plurality of second sublayers, which are alternately disposed, the semiconductor structureemits ions of indium, aluminum, a first dopant, and a second dopant whenprimary ions are irradiated thereon, an intensity of the indium ionsemitted from the active layer includes a maximum indium intensity peak,a doping concentration of the first dopant emitted from the firstconductive semiconductor layer includes a maximum concentration peak,the maximum indium intensity peak is disposed to be spaced apart fromthe maximum concentration peak in a first direction, an intensity of theindium ions emitted from the plurality of first sub layers has aplurality of first indium intensity peaks, a doping concentration of thefirst dopant emitted from the plurality of first sub layers has aplurality of first concentration peaks, and the plurality of firstindium intensity peaks and the plurality of first concentration peaksare disposed between the maximum indium intensity peak and the maximumconcentration peak.

An intensity of the indium ions emitted from the plurality of second sublayers may have a plurality of first valleys, a doping concentration ofthe first dopant emitted from the plurality of second sub layers mayhave a plurality of second valleys, and the first valleys may increasein intensity as it approaches the maximum indium intensity peak.

The first conductive semiconductor layer may include a secondsuperlattice layer disposed between the active layer and the firstsuperlattice layer, the second superlattice layer may include aplurality of third sub layers and a plurality of fourth sub layers,which are alternately disposed, an intensity of the indium ions emittedfrom the third sub layers may have a second indium intensity peak higherthan the first indium intensity peak, and the second indium intensitypeak may be disposed between the maximum indium intensity peak and thefirst indium intensity peak.

The doping concentration of the first dopant may include a secondconcentration peak and a third concentration peak that are disposed tobe spaced apart from the first concentration peak in the firstdirection, the second concentration peak and the third concentrationpeak may be higher than the first concentration peak, and the secondconcentration peak may be higher than the third concentration peak.

The second concentration peak may be disposed between the second indiumintensity peak and the maximum indium intensity peak.

The first dopant may include a fourth concentration peak disposed to bespaced apart in a direction opposite to the first direction, and thefourth concentration peak may be disposed between the maximumconcentration peak and the first concentration peak.

The fourth concentration peak may be higher than the first concentrationpeak.

An intensity of the aluminum ions may include a first aluminum intensitypeak having the highest ion intensity and a second aluminum intensitypeak disposed to be spaced apart from the first aluminum intensity peakin a direction opposite to the first direction, and the maximum indiumintensity peak may be disposed between the first aluminum intensity peakand the second aluminum intensity peak.

The second indium intensity peak and the second aluminum intensity peakmay be disposed at the same position.

The first sub layers may include InN, the second sub layers may includeGaN, the first sub layers may have a thickness of 2 nm to 4 nm, and thesecond sub layers may have a thickness of 20 nm to 40 nm.

Advantageous Effects

According to one embodiment of the present invention, a surfaceroughness of a semiconductor layer can be improved and thus opticalpower and/or current spreading efficiency can be improved.

Various advantages and effects of the present invention are not limitedto the above description and can be more easily understood during thedescription of specific exemplary embodiments of the present invention.

DESCRIPTION OF DRAWINGS

FIG. 1 is a conceptual diagram of a semiconductor device according toone embodiment of the present invention.

FIG. 2 is a diagram illustrating an energy bandgap of the semiconductordevice according to one embodiment of the present invention.

FIG. 3 is a view illustrating a surface roughness of the semiconductordevice according to one embodiment of the present invention.

FIG. 4 is a view illustrating a surface roughness of a conventionalsemiconductor device.

FIG. 5 illustrates secondary-ion mass spectrometry (SIMS) data of thesemiconductor device according to one embodiment of the presentinvention.

FIG. 6 is a view illustrating an ion intensity of each of a first dopantand indium.

FIG. 7 is a view illustrating a doping concentration of each of thefirst dopant and a second dopant.

FIG. 8 is a view illustrating an ion intensity of aluminum.

FIG. 9 is a graph obtained by measuring optical power of thesemiconductor device according to one embodiment of the presentinvention.

FIG. 10 is a graph obtained by measuring voltage and current applied tothe semiconductor device according to one embodiment of the presentinvention.

FIG. 11 is a graph obtained by measuring external light extractionefficiency of the semiconductor device according to one embodiment ofthe present invention.

FIG. 12 is a graph obtained by measuring wall-plug efficiency (WPE) ofthe semiconductor device according to one embodiment of the presentinvention.

MODES OF THE INVENTION

The present embodiments may be modified in other forms, or severalembodiments may be combined with one another, and the scope of thepresent invention is not limited to each of the embodiments describedbelow.

Even when content described in a specific embodiment is not described inother embodiments, the content may be understood as being related toother embodiments unless described otherwise or the content contradictsa specific embodiment in the other embodiments.

For example, when features of component A are described in a specificembodiment and features of component B are described in anotherembodiment, it should be understood that embodiments in which componentA is combined with component B fall within the scope and spirit of thepresent invention even when they are not explicitly described, unlessthere is an opposing or contradictory explanation.

In the description of the embodiments, when an element is referred to asbeing “on or under” another element, the term “on or under” refers toeither a direct connection between two elements or an indirectconnection between two elements having one or more elements formedtherebetween. In addition, when the term “on or under” is used, it mayrefer to a downward direction as well as an upward direction withrespect to an element.

Hereinafter, embodiments of the present invention will be described indetail with reference to the accompanying drawings so that those ofordinary skill in the art can easily implement them.

FIG. 1 is a conceptual diagram of a semiconductor device according toone embodiment of the present invention, FIG. 2 is a diagramillustrating an energy bandgap of the semiconductor device according toone embodiment of the present invention, FIG. 3 is a view illustrating asurface roughness of the semiconductor device according to oneembodiment of the present invention, and FIG. 4 is a view illustrating asurface roughness of a conventional semiconductor device.

Referring to FIGS. 1 to 3, the semiconductor device according to theembodiment may include a substrate 110, a semiconductor structure 170disposed on the substrate 110, and a first electrode 161 and a secondelectrode 162 that are disposed on the semiconductor structure 170.

The substrate 110 may include a conductive substrate or an insulatingsubstrate. The substrate 110 may be a material suitable for growing asemiconductor material or may be a carrier wafer. The substrate 110 maybe made of a material selected from the group consisting of sapphire(Al₂O₃), SiC, GaAs, GaN, ZnO, Si, GaP, InP, and Ge, but the presentinvention is not limited thereto.

A first conductive semiconductor layer 120 may be implemented with acompound semiconductor including a III-V group element, a II-VI groupelement, or the like and may be doped with a first dopant. The firstconductive semiconductor layer 120 may be made of semiconductormaterials having a composition formula of In_(x1)Al_(y1)Ga_(1-x1-y1)N(0<=x1<=1, 0<=y1<=1, and 0<=x1+y1<=1), for example, semiconductormaterials selected from among GaN, AlGaN, InGaN, InAlGaN, and the like.

The first dopant may be an n-type dopant such as Si, Ge, Sn, Se, and Te.When the first dopant is an n-type dopant, the first conductivesemiconductor layer 120 doped with the first dopant may be an n-typesemiconductor layer.

The first conductive semiconductor layer 120 may include a firstsuperlattice layer 122 and a second superlattice layer 123. The firstsuperlattice layer 122 may include a first sub layer 122 a and a secondsub layer 122 b that are alternately disposed. The first sub layer 122 amay include indium. As an example, the first sub layer 122 a may includeInN and the second sub layer 122 b may include GaN, but the presentinvention is not necessarily limited thereto.

Both the first sub layer 122 a and the second sub layer 122 b may alsoinclude InGaN. In this case, the composition of InGaN in the first sublayer 122 a and the composition of InGaN in the second sub layer 122 bmay be different from each other. For example, the composition of indium(In) in the first sub layer 122 a may be higher than the composition ofindium (In) in the second sub layer 122 b.

The first sub layer 122 a may have a thickness of 2 nm to 4 nm, and thesecond sub layer 122 b may have a thickness of 20 nm to 40 nm. That is,the first sub layer 122 a may be thinner than the second sub layer 122b.

The first superlattice layer 122 may be a semiconductor layer grown at alow temperature to form concavo-convex portions V1 having a V-shapedcross section. The concavo-convex portions may relieve the strain of thefirst conductive semiconductor layer 120 and an active layer 130 and mayprevent the dislocation from extending to the active layer 130 and asecond conductive semiconductor layer 150, thereby improving the qualityof the semiconductor device.

As an example, the first conductive semiconductor layer 120 may be grownat about 1000° C., and the first superlattice layer 122 may be grown atabout 700° C. to form the concavo-convex portion. However, in this case,as shown in FIG. 3, there is a problem in that groove-shaped defects U1are formed on the surface of the semiconductor layer at the periphery ofthe concavo-convex portion V1. Accordingly, the surface roughness of theactive layer may be increased and the applied stress may be increased.Thus, optical power may be lowered.

On the other hand, referring to FIG. 4, in the semiconductor deviceaccording to the embodiment, it can be seen that the density of theconcavo-convex portions V1 is maintained while the groove-shaped defectsU1 are reduced by forming the first superlattice layer 122 on the firstconductive semiconductor layer 120. That is, according to theembodiment, by forming the first superlattice layer 122 on the firstconductive semiconductor layer 120, the surface morphology of thesemiconductor layer and the stress of the active layer 130 may becontrolled before growing the active layer 130. Accordingly, optical andelectrical characteristics of the semiconductor device may be improved.

Referring to FIG. 1 again, the first sub layer 122 a and the second sublayer 122 b may be doped with a first dopant. The first dopant may be ann-type dopant such as Si, Ge, Sn, Se, and Te. When the first dopant isan n-type dopant, the first sub layer 122 a and the second sub layer 122b, which are doped with the first dopant, may be n-type semiconductorlayers.

A doping concentration of the first sub layer 122 a may be higher than adoping concentration of the second sub layer 122 b. When both the firstsub layer 122 a and the second sub layer 122 b are sufficiently dopedwith the first dopant, it may be beneficial for electrostatic discharge(ESD), but a reverse voltage VR may be lowered significantly.Accordingly, in the embodiment, capacitance may be increased withoutsignificantly lowering the level of the reverse voltage VR by furtherdoping the first dopant into the first sub layer 122 a that is thinnerthan the second sub layer 122 b, thereby achieving ESD improvement. Asan example, the first sub layer 122 a may have a doping concentration of2×10¹⁸ cm⁻³ to 3×10¹⁸ cm⁻³, and the second sub layer 122 b may have adoping concentration of 0.5×10¹⁸ cm⁻³ to 1.5×10¹⁸ cm⁻³, but the presentinvention is not necessarily limited thereto.

The second superlattice layer 123 may include a third sub layer 123 aand a fourth sub layer 123 b that are alternately disposed. The thirdsub layer 123 a may include InGaN, and the fourth sub layer 123 b mayinclude AlGaN. The second superlattice layer 123 may serve to relievethe stress of the active layer 130 and to spread current.

The active layer 130 may be disposed between the first conductivesemiconductor layer 120 and the second conductive semiconductor layer150. The active layer 130 is a layer at which electrons (or holes)injected through the first conductive semiconductor layer 120 and holes(or electrons) injected through the second conductive semiconductorlayer 150 meet. As the electrons and the holes are recombined andtransitioned to a low energy level, the active layer 130 may generatelight.

According to the embodiment, before the active layer 130 is grown, thesurface roughness is improved due to the first superlattice layer 122 sothat the stress applied to the active layer 130 may be relieved toenhance optical power.

The active layer 130 may have one structure among a single wellstructure, a multi-well structure, a single quantum well structure, amulti-quantum well (MQW) structure, a quantum dot structure, and aquantum wire structure, but the structure of the active layer 130 is notlimited thereto. As an example, the active layer may generate blue lighthaving a wavelength band of 450 nm, but the present invention is notnecessarily limited thereto

The second conductive semiconductor layer 150 may be formed on theactive layer 130 and implemented with a compound semiconductor includinga III-V group element, a II-VI group element, or the like, and thesecond conductive semiconductor layer 150 may be doped with a seconddopant. The second conductive semiconductor layer 150 may be made ofsemiconductor materials having a composition formula ofIn_(x5)Al_(y2)Ga_(1-x5-y2)N (0<=x5<=1, 0<=y2<=1, and 0<=x5+y2<=1) ormaterials selected from among AlInN, AlGaAs, GaP, GaAs, GaAsP, andAlGaInP. When the second dopant is a p-type dopant such as Mg, Zn, Ca,Sr, Ba, or the like, the second conductive semiconductor layer 150 dopedwith the second dopant may be a p-type semiconductor layer.

A blocking layer 140 may be disposed between the active layer 130 andthe second conductive semiconductor layer 150. The blocking layer 140may block electrons supplied from the first conductive semiconductorlayer 120 from flowing out to the second conductive semiconductor layer150, thereby increasing the probability that electrons and holes arerecombined with each other in the active layer 130. An energy band gapof the blocking layer 140 may be greater than an energy band gap of theactive layer 130 and/or the second conductive semiconductor layer 150.

The blocking layer 140 may be selected from semiconductor materialshaving a composition formula of In_(x1)Al_(y1)Ga_(1-x1-y1)N(0<=x1<=1,0<=y1<=1, and 0<=x1+y1<=1), for example, semiconductor materialsselected from among AlGaN, InGaN, InAlGaN, and the like, but the presentinvention is not necessarily limited thereto.

Each of the first electrode 161 and the second electrode 162 may beformed to include at least one among indium tin oxide (ITO), indium zincoxide (IZO), indium zinc tin oxide (IZTO), indium aluminum zinc oxide(IAZO), indium gallium zinc oxide (IGZO), indium gallium tin oxide(IGTO), aluminum zinc oxide (AZO), antimony tin oxide (ATO), galliumzinc oxide (GZO), IZO nitride (IZON), Al—Ga ZnO (AGZO), In—Ga ZnO(IGZO), ZnO, IrOx, RuOx, NiO, RuOx/ITO, Ni/IrOx/Au, Ni/IrOx/Au/ITO, Ag,Ni, Cr, Ti, Al, Rh, Pd, Ir, Sn, In, Ru, Mg, Zn, Pt, Au, and Hf, but thepresent invention is not limited thereto.

FIG. 5 illustrates secondary-ion mass spectrometry (SIMS) data of thesemiconductor device according to one embodiment of the presentinvention, FIG. 6 is a view illustrating an ion intensity of each of afirst dopant and indium, FIG. 7 is a view illustrating a dopingconcentration of each of a first dopant and a second dopant, and FIG. 8is a view illustrating an ion intensity of aluminum.

Referring to FIG. 5, a semiconductor structure may include indium (In),aluminum (Al), gallium (Ga), a first dopant, and a second dopant eachhaving a secondary ion intensity that changes in a first direction D1that is a direction toward the second conductive semiconductor layer 150from the first conductive semiconductor layer 120. A first dopant(dopant 1) may be silicon (Si), and a second dopant (dopant 2) may bemagnesium (Mg), but the present invention is not necessarily limitedthereto.

SIMS data may be data that is analyzed through Time-of-Flight SecondaryIon Mass Spectrometry (TOF-SIMS).

SIMS data may be obtained by analyzing secondary ions that are emittedfrom a target surface to which primary ions are irradiated. In thiscase, the primary ions may be selected from among O₂ ⁺, Cs⁺, Bi⁺, andthe like. As an example, an acceleration voltage may be adjusted withinthe range of 20 keV to 30 keV, an irradiated current may be adjustedwithin the range of 0.1 pA to 5.0 pA, and an area where the irradiationis achieved may be 20 nm×20 nm, but the present invention is notnecessarily limited thereto.

SIMS data may be obtained by collecting a secondary ion mass spectrumwhile gradually etching a surface S0 (a point with a depth of zero) ofthe second conductive semiconductor layer 150 in a direction toward thefirst conductive semiconductor layer 120.

Also, results of the SIMS analysis may be obtained by interpreting aspectrum for a secondary ion intensity or doping concentration of thematerial. When the secondary ion intensity or doping concentration isinterpreted, the results may include noise occurring within 0.9 times to1.1 times. Accordingly, the term “the same/identical” refers toincluding noise within 0.9 times to 1.1 times of a specific secondaryion intensity or doping concentration.

The indium, the aluminum, and the gallium in the SIMS data are spectrumdata for the ion intensity, and the first dopant and the second dopantare data obtained by calculating spectrum data for the dopingconcentration. That is, referring to FIGS. 5, 6, and 7, the first andsecond dopants may refer to concentration (atoms/cm³) units, and theindium, the aluminum, and the gallium may refer to secondary ionintensity (counts/sec.) units.

The method of calculating the doping concentration data of the firstdopant and the second dopant is not particularly limited. In addition,in the present embodiment, a longitudinal axis (i.e., a Y-axis) isconverted to a logarithmic scale and illustrated.

The ion intensity according to the embodiment may increase or decreasedepending on measurement conditions. However, a secondary ion intensity(e.g., for an aluminum ion) may generally increase on the graph when aprimary ion intensity increases and may generally decrease on the graphwhen the primary ion intensity decreases. Accordingly, the change in ionintensity in a thickness (depth) direction may be similar even when themeasurement conditions are changed.

Referring to FIGS. 6 and 7, an indium ion intensity may have a pluralityof first indium intensity peaks N1 in a region of a plurality of firstsub layers 122 a, and a doping concentration of the first dopant mayhave a plurality of first concentration peaks Si in the plurality offirst sub layers 122 a.

Further, in a plurality of second sub layers 122 b, an indium ionintensity may have a plurality of first valleys N12, and a dopingconcentration of the first dopant may have a plurality of second valleysS12. Here, the first valleys N12 may increase in intensity as it goes inthe first direction D1.

That is, the first indium intensity peaks N1 and the first concentrationpeaks S1 may be disposed at the same position, and the first valleys N12and the second valleys S12 may also be disposed at the same position. Inaddition, the first concentration peak S1 may have a higher dopingconcentration than the second valley S12. According to such aconfiguration, the first dopant is intensively doped into the relativelythin first sub layer 122 a, and thus ESD improvement may be achievedwhile preventing a reverse voltage level from being excessively lowered.

That is, the intensity of indium ions emitted from the plurality offirst sub layers 122 a may have the plurality of first indium intensitypeaks N1, the doping concentration of the first dopant emitted from theplurality of first sub layers 122 a may have the plurality of firstconcentration peaks S1, and the plurality of first indium intensitypeaks N1 and the plurality of first concentration peaks S1 may bedisposed between a third indium intensity peak N3 and a fifthconcentration peak S5.

The indium ion intensity may have a second indium intensity peak N2 andthe third indium intensity peak N3 that are disposed to be spaced apartfrom the first indium intensity peak N1 in the first direction D1. Here,the second indium intensity peak N2 and the third indium intensity peakN3 may have an ion intensity higher than that of the first indiumintensity peak N1, and the third indium intensity peak N3 may have anion intensity higher than that of the second indium intensity peak N2.The third indium intensity peak N3 may be the maximum indium intensitypeak in a light-emitting structure.

The second indium intensity peak N2 may be an ion intensity in thesecond superlattice layer 123, and the third indium intensity peak N3may be an indium ion intensity in the active layer 130. Accordingly, thenumber of the second indium intensity peaks N2 may be equal to thenumber of the third sub layers 123 a of the second superlattice layer123, and the number of the third indium intensity peak N3 may be equalto the number of well layers.

The doping concentration of the first dopant may include a secondconcentration peak S2 and a third concentration peak S3 disposed to bespaced apart from the first concentration peak S1 in the first directionD1. Here, the second concentration peak S2 and the third concentrationpeak S3 may be higher than the first concentration peak S1, and thesecond concentration peak S2 may be higher than the third concentrationpeak S3.

The second concentration peak S2 may be disposed in a region between theactive layer 130 and the first conductive semiconductor layer 120. Thatis, the second concentration peak S2 may be disposed between the secondindium intensity peak N2 and the third indium intensity peak N3. Thesecond concentration peak S2 may have a relatively high dopingconcentration of the first dopant in order to increase the moving speedof first carriers. Accordingly, since the moving speed of the firstcarriers injected into the active layer 130 is increased, electroninjection efficiency may be enhanced and optical power may be improved.

The first dopant may further include a fourth concentration peak S4 andthe fifth concentration peak S5 disposed to be spaced apart from eachother in a direction opposite to the first direction D1. The fifthconcentration peak S5 may be the maximum concentration peak among thedoping concentrations of the first dopant.

The fourth concentration peak S4 may have an ion intensity lower thanthat of the fifth concentration peak S5 and higher than that of thefirst concentration peak S1. According to the embodiment, the intensityof the first dopant is lowered in the region in which the fourthconcentration peak S4 is disposed so that operating voltage improvementmay be achieved.

The doping concentration of the second dopant may be highest on asurface S0 and may gradually decrease away from the surface. Inaddition, the second dopant may have a reverse section (a sectionbetween M1 and M2) in which the concentration increases away from thesurface.

The second dopant may be present in all regions of the second conductivesemiconductor layer 150 and some regions of the active layer 130, butthe present invention is not necessarily limited thereto. The seconddopant may be disposed in only the second conductive semiconductor layer150 but may diffuse up to the active layer 130. Accordingly, it ispossible to improve injection efficiency for the second dopant injectedinto the active layer 130. However, when the second dopant diffuses upto the first conductive semiconductor layer 120, a leakage current ofthe semiconductor device and/or non-radiative recombination betweenfirst and second carriers may occur, thereby reducing reliability and/orlight-emitting efficiency of the semiconductor device.

Referring to FIG. 6, the third indium intensity peak N3 having thehighest indium ion intensity and the fifth concentration peak S5 havingthe highest concentration of the first dopant may be disposed to bespaced apart from each other in the first direction D1. A referenceregion R5 including the third indium intensity peak N3 may be the activelayer.

The reference region R5 may further include a plurality of sections inwhich an indium ion intensity increases and decreases in the firstdirection and/or the direction opposite to the first direction withrespect to the third indium intensity peak N3, and it has a high pointand a low point at points at which the increasing section and thedecreasing section are in contact.

When the active layer is composed of a plurality of well layers and aplurality of blocking layers, the plurality of well layers may each bethe high point having a high indium ion intensity, and the plurality ofblocking layers may each be the low point having a low indium ionintensity. In addition, the high and low points of the active layer mayeach have an ion intensity within 10% error relative to the third indiumintensity peak N3. Thus, energy band gaps of the well layers may beconfigured relatively uniformly, and the wavelength of light emittedfrom each of the well layers may be uniformly controlled.

A first region R1 including the fifth concentration peak S5, which hasthe highest first dopant concentration, may include a point at which theindium ion intensity is the lowest (or a point serving as a referencefor the indium ion intensity). Accordingly, the stress between theactive layer and the substrate may be relieved while having a high firstcarrier concentration.

The first region R1 may have a first dopant concentration similar tothat of the fifth concentration peak S5. Specifically, the dopingconcentration in the first region R1 and the fifth concentration peak S5may have a relatively uniform concentration within 5% error.Accordingly, the stress generated between the substrate and the activelayer may be relieved and crystal defects may be improved by configuringthe indium ion intensity between the active layer and the first regionR1 to be low. Here, the phrase “the indium ion intensity is lowered” maymean that the indium ion intensities of a plurality of high and/or lowpoints are steadily lowered or gradually lowered.

A second region R2 may be disposed between the reference region R5 andthe first region R1, and the second region R2 may be disposed in contactwith the first region R1. The second region R2 may have a relativelyuniform concentration within 5% error relative to the fourthconcentration peak S4. In addition, the second region R2 may have anindium ion intensity similar to the indium ion intensity of the firstregion R1. The second region R2 has a dopant concentration lower thanthe first dopant concentration of the first region R1, thereby improvinga diffusion function of the first carriers.

A third region R3 may be disposed between the reference region R5 andthe second region R2. The third region R3 may be disposed in contactwith the second region R2. The second region R2 may have a plurality ofsections in which the indium ion intensity increases along the firstdirection D1 and a plurality of sections in which the indium ionintensity decreases along the first direction D1, and each of theplurality of increasing sections and each of the plurality of decreasingsections may be in contact with each other. Accordingly, the indium ionintensity may have a plurality of peaks N1 and a plurality of valleysN12 in the third region R3.

In addition, a first dopant concentration of the third region R3 mayhave a plurality of increasing sections and a plurality of decreasingsections along the first direction D1, and each of the plurality ofincreasing sections and each of the plurality of decreasing sections maybe in contact with each other. Accordingly, the first dopantconcentration may have a plurality of peaks Si and a plurality ofvalleys S12 in the third region R3.

A high point of the first dopant in the third region R3 may be disposedbetween the section in which the indium ion intensity of the thirdregion R3 increases along the first direction and the section in whichthe indium ion intensity of the third region R3 decreases along thefirst direction. In addition, the high point of the first dopant in thethird region R3 may be disposed in the same region as a high point ofthe indium ion intensity of the third region R3. In this case, ESDimprovement may be achieved while preventing a reverse voltage levelfrom being excessively lowered.

The plurality of peaks N1 of the indium ion intensity in the thirdregion R3 may have a relatively uniform ion intensity within 10%. Inaddition, the plurality of valleys N12 of the indium ion intensity inthe third region R3 may have a higher indium ion intensity in the firstdirection. In addition, the difference between the peak N1 and thevalley N12 of the indium ion intensity, which are closest to each other,may gradually decrease along the first direction D1. Accordingly, thestress generated due to the difference between a lattice constant of thesubstrate and/or the first region R1 and a lattice constant of theactive layer may be relieved.

A region in which the first region R1 is in contact with the secondregion R2 may have a first slope SP1, which is an average change amountof the first dopant concentration with respect to a depth change amount,between the first dopant concentration of the first region R1 and thefirst dopant concentration of the second region R2.

Also, a region in which the second region R2 is in contact with thethird region R3 may have a second slope SP2, which is an average changeamount of the first dopant concentration with respect to a depth changeamount, between the first dopant concentration of the second region R2and the first dopant concentration of the third region R3.

The first slope SP1 may be gentler than the second slope SP2.Accordingly, the difference in the amount of change of the firstcarriers between the first region R1 and the second region R2 may beminimized as much as possible, and the difference in the electric fielddue to the change amount of the first carriers is reduced so thatinternal electric field may be reduced, thereby suppressing a phenomenonin which a wavelength changes according to the internal electric field.

A fourth region R4 may be disposed between the third indium intensitypeak N3 and the third region R3. The fourth region R4 may have aplurality of sections in which an indium ion intensity decreases alongthe first direction and a plurality of sections in which the indium ionintensity increases along the first direction, and a peak pointincluding a high point and/or a low point may be included in a region inwhich each of the plurality of sections in which the indium ionintensity decreases is in contact with each of the plurality of sectionsin which the indium ion intensity increases.

The low point of the fourth region R4 may be higher than the high pointof the third region R3 and may be lower than the ion intensity peak ofthe active layer. Accordingly, the stress caused by a lattice constantdifference between the substrate and the active layer and/or between theactive layer and the third region R3 may be relieved. In addition, adistance between the high point and the low point of the indium ionintensity adjacent to each other in the fourth region R4 may be lessthan a distance between the high point and the low point of the indiumion intensity adjacent to each other in the third region R3. Thus,crystal defects extending from the third region R3 to the active layermay be reduced, and the crystal quality of the active layer may beimproved, thereby improving optical power and electrical characteristicsof a light-emitting device.

The fourth region R4 and the reference region R5 may be in contact witheach other, and a region in which the fourth region R4 is in contactwith the reference region R5 may have a first dopant concentration thatis higher than the first dopant concentration of the second region R2and lower than the first dopant concentration of the first region R1. Inaddition, the first dopant concentration of the region in which thefourth region R4 is in contact with the reference region R5 may haveincreasing sections and decreasing sections along the first direction,and a contact point at which the two sections are in contact with eachother may be the second concentration peak S2. Accordingly, the opticalpower of the light-emitting device may be improved by increasing theconcentration of the first carriers injected into the active layer.

According to the embodiment, the first region R1 and the second regionR2 may be regions corresponding to the first conductive semiconductorlayer, the third region R3 may be a region corresponding to the firstsuperlattice layer, the fourth region R4 may be a region correspondingto the second superlattice layer, the fifth region R5 may be a regioncorresponding to the active layer, and a sixth region R6 may be a regioncorresponding to the second conductive semiconductor layer and theblocking layer.

Referring to FIGS. 5 and 8, an aluminum ion intensity may include afirst aluminum peak A1 having the highest ion intensity and a secondaluminum peak A2 disposed to be spaced apart from the first aluminumpeak A1 in the direction opposite to the first direction. The firstaluminum peak A1 may be disposed in a region of the blocking layer 140,and the second aluminum peak A2 may be disposed in the superlatticelayer. Accordingly, the third indium intensity peak N3 disposed in theregion of the active layer 130 may be disposed between the firstaluminum peak A1 and the second aluminum peak A2.

The second indium intensity peak N2 and the second aluminum peak A2 maybe disposed at the same position of the second superlattice layer 123.

The first indium intensity peak N1 may be disposed between the thirdintensity peak N3 having the highest indium ion intensity and the fifthconcentration peak S5 having the highest first dopant concentration. Inaddition, the first indium intensity peak N1 may be disposed between thefifth concentration peak S5 and the second indium intensity peak N2 thatis disposed at the same position as the second aluminum peak A2. Thenumber of first indium intensity peaks N1 may be plural.

The first concentration peak S1 may be disposed at the same position(depth) as the first indium intensity peak N1. The first indiumintensity peaks N1 and the first valleys N12 may be alternatelydisposed, and the second concentration peaks S1 and the second valleysS12 may be alternately disposed. Here, the first valley N12 and thesecond valley S12 may be disposed at the same position (depth).

FIG. 9 is a graph obtained by measuring optical power of thesemiconductor device according to one embodiment of the presentinvention, FIG. 10 is a graph obtained by measuring voltage and currentapplied to the semiconductor device according to one embodiment of thepresent invention, FIG. 11 is a graph obtained by measuring externallight extraction efficiency of the semiconductor device according to oneembodiment of the present invention, and FIG. 12 is a graph obtained bymeasuring wall-plug efficiency (WPE) of the semiconductor deviceaccording to one embodiment of the present invention.

Referring to FIG. 9, it can be seen that the embodiment in which thefirst sub layer 122 a and the second sub layer 122 b are disposed has anoptical power Po increased compared to a conventional semiconductordevice. In addition, it can be seen that current-voltage characteristicsare improved as shown in FIG. 10, external light extraction efficiencyis also improved as shown in FIG. 11, and WPE is also improved as shownin FIG. 12.

The semiconductor device may be applied to various types of light sourcedevices. For example, the light source devices may be concepts includinga lighting device, a display device, and a vehicle lamp. That is, thesemiconductor device may be disposed in a case and applied to variouselectronic devices configured to provide light.

The lighting device may include a light source module having thesubstrate 110 and the semiconductor device of the embodiment, a heatdissipation part configured to dissipate heat of the light sourcemodule, and a power supply configured to process or convert anelectrical signal provided from the outside to provide the electricalsignal to the light source module. In addition, the lighting device mayinclude a lamp, a head lamp, a street light, or the like.

The display device may include a bottom cover, a reflective plate, alight-emitting module, a light guide plate, an optical sheet, a displaypanel, an image signal output circuit, and a color filter. The bottomcover, the reflective plate, the light-emitting module, the light guideplate, and the optical sheet may constitute a backlight unit.

The reflective plate may be placed on the bottom cover, and thelight-emitting module may emit light. The light guide plate may beplaced in front of the reflective plate to guide light emitted by thelight-emitting module forward, and the optical sheet may include a prismsheet or the like and may be placed in front of the light guide plate.The display panel may be placed in front of the optical sheet, the imagesignal output circuit may supply an image signal to the display panel,and the color filter may be placed in front of the display panel.

When the semiconductor device is used as a backlight unit of a displaydevice, the semiconductor device may be used as an edge-type backlightunit or a direct-type backlight unit.

The semiconductor device may be a laser diode in addition to theabove-described light-emitting diode.

Like the light-emitting device, the laser diode may include a firstconductive semiconductor layer 120, an active layer 130, and a secondconductive semiconductor layer 150 that have the above-describedstructures. In addition, the laser diode may utilize anelectroluminescence phenomenon in which light is emitted when currentflows after bonding a p-type first conductive semiconductor and ann-type second conductive semiconductor, but has a difference in thedirectionality and phase of the emitted light. That is, the laser diodeuses stimulated emission and constructive interference phenomena so thatlight having a specific single wavelength (monochromatic beam) may beemitted at the same phase and in the same direction. Due to thesecharacteristics, the laser diode may be used for an opticalcommunication or medical device, a semiconductor processing device, orthe like.

A light-receiving device may include, for example, a photodetector,which is a kind of transducer configured to detect light and convert theintensity of the light into an electric signal. Such a photodetectorincludes a photocell (silicon or selenium), a photoconductor element(cadmium sulfide or cadmium selenide), a photodiode (PD) (for example, aPD having a peak wavelength in a visible blind spectral region or a trueblind spectral region), a phototransistor, a photomultiplier tube, aphototube (vacuum or gas-filled), an infra-red (IR) detector, and thelike, but the embodiment is not limited thereto.

In addition, the semiconductor device such as the photodetector maygenerally be manufactured using a direct bandgap semiconductor having ahigh photoconversion efficiency. Alternatively, the photodetector hasvarious structures and the most common structure may include a pin-typephotodetector using a p-n junction, a Schottky-type photodetector usinga Schottky junction, a metal-semiconductor-metal (MSM)-typephotodetector, or the like.

Like the light-emitting device, the photodiode may include a firstconductive semiconductor layer 120, an active layer 130, and a secondconductive semiconductor layer 150 that have the above-describedstructures and may be formed as a p-n junction or pin structure. Thephotodiode operates when a reverse bias or a zero bias is applied, andwhen light is incident on the photodiode, electrons and holes aregenerated such that current flows. In this case, the magnitude ofcurrent may be approximately proportional to the intensity of lightincident on the photodiode.

A photocell or a solar cell, which is a kind of photodiode, may convertlight into current. Like the light-emitting device, the solar cell mayinclude a first conductive semiconductor layer 120, an active layer 130,and a second conductive semiconductor layer 150 that have theabove-described structures.

Also, the solar cell may be used as a rectifier of an electronic circuitthrough the rectification characteristics of a general diode using a p-njunction and may be applied to an ultra-high frequency circuit and thenan oscillation circuit or the like.

Also, the above-described semiconductor device is not necessarilyimplemented only with semiconductors, and may further include a metalmaterial in some cases. For example, the semiconductor device such as alight-receiving device may be implemented using at least one of Ag, Al,Au, In, Ga, N, Zn, Se, P, and As and may be implemented using anintrinsic semiconductor material or a semiconductor material doped witha p-type dopant or an n-type dopant.

While the embodiments have been mainly described, they are only examplesbut do not limit the present invention, and it may be known to thoseskilled in the art that various modifications and applications, whichhave not been described above, may be made without departing from theessential properties of the embodiments. For example, the specificcomponents described in the embodiments may be implemented while beingmodified. In addition, it will be interpreted that differences relatedto the modifications and applications fall within the scope of thepresent invention defined by the appended claims.

1.-10. (canceled)
 11. A semiconductor device comprising: a semiconductorstructure including a first conductive semiconductor layer, a secondconductive semiconductor layer, and an active layer disposed between thefirst conductive semiconductor layer and the second conductivesemiconductor layer, wherein the first conductive semiconductor layerincludes a first superlattice layer including a plurality of first sublayers and a plurality of second sub layers, which are alternatelydisposed, the semiconductor structure emits ions of indium, aluminum, afirst dopant, and a second dopant when primary ions are irradiatedthereon, an intensity of the indium ions emitted from the plurality offirst sub layers has a plurality of first indium intensity peaks, and adoping concentration of the first dopant emitted from the plurality offirst sub layers has a plurality of first concentration peaks.
 12. Thesemiconductor device of claim 11, wherein an intensity of the indiumions emitted from the active layer includes a maximum indium intensitypeak, a doping concentration of the first dopant emitted from the firstconductive semiconductor layer includes a maximum concentration peak,and the maximum indium intensity peak is disposed to be spaced apartfrom the maximum concentration peak in a first direction.
 13. Thesemiconductor device of claim 12, wherein the plurality of first indiumintensity peaks and the plurality of first concentration peaks aredisposed between the maximum indium intensity peak and the maximumconcentration peak.
 14. The semiconductor device of claim 13, wherein anintensity of the indium ions emitted from the plurality of second sublayers has a plurality of first valleys, and a doping concentration ofthe first dopant emitted from the plurality of second sub layers has aplurality of second valleys.
 15. The semiconductor device of claim 14,wherein the first valleys increase in intensity as it approaches themaximum indium intensity peak.
 16. The semiconductor device of claim 13,wherein the first conductive semiconductor layer includes a secondsuperlattice layer disposed between the active layer and the firstsuperlattice layer, the second superlattice layer includes a pluralityof third sub layers and a plurality of fourth sub layers, which arealternately disposed, and an intensity of the indium ions emitted fromthe third sub layers has a second indium intensity peak higher than thefirst indium intensity peak.
 17. The semiconductor device of claim 16,wherein the second indium intensity peak is disposed between the maximumindium intensity peak and the first indium intensity peak.
 18. Thesemiconductor device of claim 17, wherein the doping concentration ofthe first dopant includes a second concentration peak and a thirdconcentration peak that are disposed to be spaced apart from the firstconcentration peak in the first direction, and the second concentrationpeak and the third concentration peak are higher than the firstconcentration peak.
 19. The semiconductor device of claim 18, whereinthe second concentration peak is higher than the third concentrationpeak.
 20. The semiconductor device of claim 19, wherein the secondconcentration peak is disposed between the second indium intensity peakand the maximum indium intensity peak.
 21. The semiconductor device ofclaim 19, wherein the first dopant includes a fourth concentration peakdisposed to be spaced apart in a direction opposite to the firstdirection, and the fourth concentration peak is disposed between themaximum concentration peak and the first concentration peak.
 22. Thesemiconductor device of claim 21, wherein the first dopant furtherincludes a fifth concentration peak disposed to be spaced apart in adirection opposite to the first direction, and the fifth concentrationpeak is higher than the first to fourth concentration peaks.
 23. Thesemiconductor device of claim 21, wherein the fourth concentration peakis higher than the first concentration peak.
 24. The semiconductordevice of claim 17, wherein an intensity of the aluminum ions includes afirst aluminum intensity peak having the highest ion intensity and asecond aluminum intensity peak disposed to be spaced apart from thefirst aluminum intensity peak in a direction opposite to the firstdirection.
 25. The semiconductor device of claim 24, wherein the maximumindium intensity peak is disposed between the first aluminum intensitypeak and the second aluminum intensity peak.
 26. The semiconductordevice of claim 25, wherein the second indium intensity peak and thesecond aluminum intensity peak are disposed at the same position. 27.The semiconductor device of claim 11, wherein the first sub layersinclude InN, and the second sub layers include GaN.
 28. Thesemiconductor device of claim 27, wherein the first sub layers have athickness of 2 nm to 4 nm, and the second sub layers have a thickness of20 nm to 40 nm.
 29. The semiconductor device of claim 11, wherein thefirst sub layers and the second sub layers all include InGaN.
 30. Thesemiconductor device of claim 29, wherein a composition of InGaN in thefirst sub layers and a composition of InGaN in the second sub layers aredifferent from each other.